[ovirt-users] Concerns with increasing vdsTimeout value on engine?

[Piotr Kliczewski]

On Mon, Jul 13, 2015 at 5:12 PM, Groten, Ryan <Ryan.Groten at stantec.com> wrote:
> Thanks for the responses everyone and for the RFE.  I do use HA in some places at the moment, but I do see another timeout value called vdsConnectionTimeout.  Would HA use this value or vdsTimeout (set to 2 by default) when attempting to contact the host?
>

There is a difference between the two:

vdsConnectionTimeout - is a timeout used during connecting to a remote
host. By default it is 2 seconds.
vdsTimeout - high level command invocation timeout used by all
commands. By default it is 3 minutes.

As far as I understand you are looking for a possibility to customize
vdsTimeout for some of the commands.


> -----Original Message-----
> From: Shubhendu Tripathi [mailto:shtripat at redhat.com]
> Sent: Monday, July 13, 2015 2:25 AM
> To: Piotr Kliczewski
> Cc: Omer Frenkel; Groten, Ryan; users at ovirt.org
> Subject: Re: [ovirt-users] Concerns with increasing vdsTimeout value on engine?
>
> On 07/13/2015 01:42 PM, Piotr Kliczewski wrote:
>> On Mon, Jul 13, 2015 at 5:57 AM, Shubhendu Tripathi <shtripat at redhat.com> wrote:
>>> On 07/12/2015 09:53 PM, Omer Frenkel wrote:
>>>>
>>>> ----- Original Message -----
>>>>> From: "Liron Aravot" <laravot at redhat.com>
>>>>> To: "Ryan Groten" <Ryan.Groten at stantec.com>
>>>>> Cc: users at ovirt.org
>>>>> Sent: Sunday, July 12, 2015 5:44:28 PM
>>>>> Subject: Re: [ovirt-users] Concerns with increasing vdsTimeout
>>>>> value on engine?
>>>>>
>>>>>
>>>>>
>>>>> ----- Original Message -----
>>>>>> From: "Ryan Groten" <Ryan.Groten at stantec.com>
>>>>>> To: users at ovirt.org
>>>>>> Sent: Friday, July 10, 2015 10:45:11 PM
>>>>>> Subject: [ovirt-users] Concerns with increasing vdsTimeout value
>>>>>> on engine?
>>>>>>
>>>>>>
>>>>>>
>>>>>> When I try to attach new direct lun disks, the scan takes a very
>>>>>> long time to complete because of the number of pvs presented to my
>>>>>> hosts (there is already a bug on this, related to the pvcreate
>>>>>> command taking a very long time -
>>>>>> https://bugzilla.redhat.com/show_bug.cgi?id=1217401 )
>>>>>>
>>>>>>
>>>>>>
>>>>>> I discovered a workaround by setting the vdsTimeout value higher
>>>>>> (it is
>>>>>> 180
>>>>>> seconds by default). I changed it to 300 seconds and now the
>>>>>> direct lun scan returns properly, but I’m hoping someone can warn
>>>>>> me if this workaround is safe or if it’ll cause other potential
>>>>>> issues? I made this change yesterday and so far so good.
>>>>>>
>>>>> Hi, no serious issue can be caused by that.
>>>>> Keep in mind though that any other operation will have that amount
>>>>> of time to complete before failing on timeout - which will cause
>>>>> delays before failing (as the timeout was increased for all
>>>>> executions)
>>>>> when not everything is operational and up as expected (as in most
>>>>> of the time).
>>>>> I'd guess that a RFE could be opened to allow increasing the
>>>>> timeout of specific operations if a user want to do that.
>>>>>
>>>>> thanks,
>>>>> Liron.
>>>> if you have HA vms and use power management (fencing), this might
>>>> cause longer downtime for HA vms if host has network timeouts:
>>>> the engine will wait for 3 network failures before trying to fence
>>>> the host, so in case of timeouts, and increasing it to 5mins, you
>>>> should expect 15mins before engine will decide host is
>>>> non-responsive and fence, so if you have HA vm on this host, this
>>>> will be the vm downtime as well, as the engine will restart HA vms
>>>> only after fencing.
>>>>
>>>> you can read more on
>>>> http://www.ovirt.org/Automatic_Fencing
>>>
>>> Even I am in a need where, I try to delete all the 256 gluster volume
>>> snapshots using a single gluster CLI command, and engine gets timed out.
>>> So, as Liron suggested it would be better if at VDSM verb level we
>>> are able to set timeout. That would be better option and caller needs
>>> to use the feature judicially :)
>>>
>> Please open a RFE for being able to set operation timeout for single
>> command call with description of use cases for which you would like to
>> set the timeout.
>
> Piotr,
>
> I created an RFE BZ at https://bugzilla.redhat.com/show_bug.cgi?id=1242373.
>
> Thanks and Regards,
> Shubhendu
>
>>>>>> Thanks,
>>>>>>
>>>>>> Ryan
>>>>>>
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>